1. Field of the Invention
This invention relates to electrical generators, and more particularly to generators that are spray-oil cooled.
2. Description of the Prior Art
Electrical generators use various cooling techniques. Generators used in aircraft are often spray oil cooled. These generators are driven by the main engine of the aircraft, and they are cooled with the oil that is shared with the main engine for its cooling and lubrication.
These spray-oil cooled electrical generators rely upon a scavenge system to remove sprayed oil from the generator and return it to the main oil supply. The scavenge system includes a scavenge pump which is driven by the same power chain as the generator. If the scavenge system becomes incapacitated, either internal to the generator or external to the generator, the oil will accumulate in the generator, and the generator will become "flooded."
Continued operation of a generator "flooded" with cooling oil can result in severe damage to the generator. Temperatures within the generator would continue to increase as a result of frictional heating imparted by the generator rotor. The trapped oil would not relieve the heat generated, and eventually, a failure of the generator housing could occur. When the generator housing fails, the result is a loss of the oil supply which is shared with the main engine, and this can cause main engine shut-down, which is an extremely dangerous situation in aircraft.
There is thus a need for design for an electric generator in aircraft which would prevent such a catastrophic failure in the event that the generator becomes flooded with oil.